Power supply structure, charging device, assembly, and image forming apparatus

Abstract

A power supply structure includes a bearing, a first spring, and a second spring. The bearing supports a rotary member that axially rotates while contacting with a contact target. While receiving power, the first spring contacts with and presses the bearing with an end portion of the first spring to bring the rotary member into contact with the contact target. The second spring extends from the first spring toward the contact target and contacts with the rotary member.

What is claimed is: 
     
       1. A power supply structure comprising:
 a bearing that supports a plurality of rotary members, the plurality of rotary members including a first rotary member that axially rotates while contacting with a contact target, and a second rotary member that axially rotates while contacting with the first rotary member; 
 a first spring that, while receiving power, contacts with and presses the bearing with an end portion of the first spring to bring the first rotary member into contact with the contact target; and 
 a second spring that extends from the first spring toward the contact target and contacts with the first rotary member, and does not contact with the second rotary member, wherein 
 a portion of the second spring that contacts the first rotary member is bent away from the first rotary member in a circular arc shape, and 
 the second rotary member is positioned between the first spring and the first rotary member. 
 
     
     
       2. The power supply structure according to  claim 1 , wherein the rotary member includes a rotary shaft and a contact portion that is provided around an outer circumference of the rotary shaft with at least one end of the rotary shaft projecting from the contact portion and contacts with the contact target, and
 wherein the second spring contacts with the outer circumference of the one end of the rotary shaft. 
 
     
     
       3. The power supply structure according to  claim 2 , further comprising protrusions that support the second spring,
 wherein the second spring supported by the protrusions contacts with the outer circumference of the one end of the rotary shaft while pressing the rotary shaft. 
 
     
     
       4. The power supply structure according to  claim 3 , wherein the protrusions are formed on the bearing. 
     
     
       5. A charging device comprising:
 the power supply structure according to  claim 1 ; and 
 a charging member that serves as the rotary member that axially rotates while contacting with the contact target, which is a member to be charged. 
 
     
     
       6. An assembly integrally comprising the charging device according to  claim 5  and the member to be charged, and attachable to a body of an image forming apparatus. 
     
     
       7. An image forming apparatus comprising:
 the charging device according to  claim 5 , 
 the member to be charged, 
 a latent image forming unit that forms a latent image on the member to be charged; 
 a developing unit that develops the latent image formed by the latent image forming unit into a toner image with toner; and 
 a transfer unit that transfers the toner image onto a medium. 
 
     
     
       8. A power supply structure comprising:
 a bearing that supports a plurality of rotary members, the plurality of rotary members including a first rotary that axially rotates while contacting with a contact target, and a second rotary member that axially rotates while contacting with the first rotary member, 
 wherein the bearing has a through-hole that is aligned in a radial direction of the contact target; 
 a first spring that, while receiving power, contacts with and presses the bearing with an end portion of the first spring to bring the first rotary member into contact with the contact target; 
 a second spring that extends from the first spring toward the contact target and contacts with the first rotary member, and does not contact with the second rotary member; and 
 protrusions that support the second spring, wherein 
 a shaft of the second rotary member is disposed in the through-hole, and 
 the protrusions are formed on the bearing and are positioned at opposite sides of the through-hole and at opposite sides of the shaft of the second rotary member. 
 
     
     
       9. A power supply structure comprising:
 a bearing that supports a plurality of rotary members, the plurality of rotary members including a first rotary member that axially rotates while contacting with a contact target, and a second rotary member that axially rotates while contacting with the first rotary member; 
 a first spring that, while receiving power, contacts with and presses the bearing with an end portion of the first spring to bring the first rotary member into contact with the contact target; 
 a second spring that extends from the first spring toward the contact target and contacts with the first rotary member, and does not contact with the second rotary member; and 
 protrusions that support the second spring, 
 wherein the protrusions are formed on the bearing and are positioned linearly with the second spring along a same side of the bearing and at opposite sides of a shaft of the second rotary member.